Direct access storage devices (DASD), commonly known as hard drives or hard disk drives (HDDs), have become part of every day life, and as such, expectations and demands continually increase for greater speed for manipulating data and for holding larger amounts of data.
In order to increase the data density upon each disk of the disk drives, the spacing between adjacent tracks of a given disk is reduced. However, the precision with which an actuator arm of the disk drive can position the read/write head over a given track may not be sufficient to provide a desired level of amplification of the recorded data. As a result, some hard disk drives utilize a microactuator/slider/suspension assembly to position the read/write head more precisely over a given track of a disk. A typical microactuator provides a range of motion for the slider with reference to the suspension assembly due to spring-like components provided by the microactuator.
When the microactuator/slider/suspension assembly is subjected to a shock such as if the slider assembly contacts the disk. For example, the friction due to the physical contact between the slider and the moving data disk creates a friction force which is transmitted to the microactuator. In another instance, when the microactuator is driven at its resonant frequency, its motion can be 10-30 times higher than when it is driven at other frequencies. These conditions may create excessive stress on the spring like components of the microactuator, thus causing deformation or breakage of the springs and failure of the microactuator.